Structure and bonding in silicon oxides and chlorides

Steps:

• Identify SiO₂ as a network solid with silicon-oxygen covalent bonds forming a giant lattice, similar to diamond.
• Determine SiCl₄ as a discrete tetrahedral molecule with polar covalent Si-Cl bonds, existing as simple molecules.
• Confirm both compounds involve covalent bonding, not ionic, due to similar electronegativities between Si and O/Cl.
• Match to option with covalent giant for SiO₂ and covalent simple for SiCl₄.

Why B is correct:

• SiO₂ forms a giant covalent structure via tetrahedral SiO₄ units sharing oxygen atoms, while SiCl₄ is a simple covalent molecule with four Si-Cl bonds, per VSEPR theory.

Why the others are wrong:

• A: SiCl₄ is simple molecular, not giant.
• C: Neither compound is ionic; silicon does not form stable ions like metals.
• D: SiO₂ bonding is covalent, not ionic.

Final answer: B